Results 31 to 40 of about 1,537 (221)
Continuous Spectra of Circumstellar Envelopes of Be Stars [PDF]
Symposium - International Astronomical Union, 1994 Line emission in Be star spectra is accompanied by continuous emission both in the Balmer continuum and in the infrared spectral region, due to the same process that is responsible for Balmer line emission, i.e. to recombination radiation from ionized hydrogen in the extended circumstellar disks surrounding the hot central stars.
D. Rohe-Koths, J. Dachs
openaire +1 more source
Odessa Astronomical Publications, 2017 The main parameters of the close binaries V448 Cyg and XZ Cep were determined. Computation of the chemical composition of the atmospheres of their primary components showed the existence of the hydrogen deficiency in them.
L. V. Glazunova, G. V. Manilova
doaj +1 more source
(New) molecular ions in the interstellar medium
EPJ Web of Conferences, 2015 We summarize the present knowledge on the molecular ionic content in the interstellar medium and in circumstellar envelopes. Emphasis is given on the most recent detections and the related chemical issues.
Roueff Evelyne
doaj +1 more source
Molecules in Circumstellar Envelopes [PDF]
Highlights of Astronomy, 1989 ABSTRACTThe chemistry of circumstellar envelopes around evolved stars is extremely rich, especially for C-rich ones. 34 molecules have been identified in IRC+10216. Recent observations and modeling prove that most of the unstable species are formed by photochemistry in the outer layers of the envelope.
openaire +1 more source
Energy Balance in Circumstellar Envelopes [PDF]
International Astronomical Union Colloquium, 2000 AbstractWe have successfully determined the kinetic temperature of the electron gas as a function of position in the circumstellar envelopes of Be stars. Our method yields a self-consistent solution of the equation for energy conservation, thus eliminating the necessity to assume arbitrarily a temperature for the gas.
C. E. Millar +2 more
openaire +1 more source
MODELS OF CIRCUMSTELLAR MASERS IN BIPOLAR OUTFLOWS
Odessa Astronomical Publications, 2017 Sources of molecular maser radio emission in envelopes of late-type variable stars (red giants and supergiants) are considered. Radio and optical data on asymmetry of mass loss process in red giants are briefly reviewed.
G. M. Rudnitskij
doaj +1 more source
The Astrophysical Journal, 2023 We obtained accurate vibrational frequencies, rotational constants, and vertical transition energy for AlNH _2 (X ^1 A _1 ) and HAlNH(X ^1 A′) isomers using ab initio calculations at various levels of theory.
Tarek Trabelsi +2 more
doaj +1 more source
Millimetre Observations of Maser-Emitting Planetary Nebulae
Galaxies, 2022 Observations in the millimetre bands of maser-emitting planetary nebulae (PNe) are crucial to study their circumstellar molecular gas at the beginning of the PN phase.
Lucero Uscanga +9 more
doaj +1 more source
Circumstellar Envelopes of OH-IR Sources [PDF]
Symposium - International Astronomical Union, 1987 This article reviews recent radio observations of maser emission from OH, H2O and SiO molecules in the circumstellar envelopes of OH-IR sources. The different radio lines require different conditions for their excitation, and each therefore probes different regions in the circumstellar envelope. For some stars radio interferometer maps of several maser
openaire +1 more source
Magnetic fields in circumstellar envelopes of evolved AGB stars [PDF]
, 2019 In this paper, a time-dependent magnetohydrodynamic model is presented which aimed at understanding the superwind production by an evolved AGB star and the consecutive formation of a dense circumstellar envelope around it. We know henceforth from various
Pascoli, Gianni
core +2 more sources